Background/Objectives: To investigate the association between dietary patterns and prevalence and incidence 3 years later of depressive symptoms using data from the mid-aged cohort in the Australian Longitudinal Study on Women's Health.Subjects/Methods: Participants (aged 50-55 years) completed a food frequency questionnaire in 2001. Depressive symptoms were measured in 2001 and 2004 using the validated 10-item Centre for Epidemiologic Studies Depression scale. Multiple logistic regression was used for cross-sectional analysis (8369 women) and longitudinal analysis (7588) to assess the associations between dietary patterns and prevalence of depressive symptoms, and then for longitudinal analysis (6060) on their associations with the incidence of depressive symptoms in 2004, while adjusting for sociodemographic and lifestyle factors.Results: Six dietary patterns were identified from factor analysis: cooked vegetables, fruit, Mediterranean style, meat and processed meat, dairy, and high fat and sugar. A higher consumption of the Mediterranean-style diet had a cross-sectional association with lower prevalence of depressive symptoms in 2001, adjusted odds ratio 0.82 (95% confidence interval 0.77-0.88); and longitudinally with lower incidence of depressive symptoms in 2004, adjusted odds ratio 0.83 (0.75-0.91). None of the associations found for other dietary patterns remained statistically significant after adjustment for confounders. A dose-response relationship was found cross-sectionally when women were grouped according to quintiles of Mediterranean-style diet (P-value for trend <0.001).Conclusions: Consumption of a 'Mediterranean-style' dietary pattern by mid-aged women may have a protective influence against the onset of depressive symptoms. These findings suggest that dietary patterns have a potential role in the prevention and management of depressive symptoms.